Dwarfism can be caused by many problems

Around 200,000 Americans 4 feet, 10 inches and under affected with a variety of condition

April 9, 2012

Dwarfism is a condition that affects about 200,000 Americans. Most commonly it is defined as an adult who is shorter than 4 feet, 10 inches.

Dwarfism, though it can be caused by many different medical conditions, may be broadly broken down into two types; disproportionate dwarfism and proportionate dwarfism. Disproportionate dwarfism is where one or more body parts are relatively large or small in proportion to overall height compared to the proportions found in the average adult. Proportionate dwarfs, who historically were called "midgets," appear to have normal body proportions but are overall small in size.

The most common cause of disproportionate dwarfism is a condition called achondroplasia. Those with achondroplasia tend to have very short legs and short arms, especially of the upper arms and legs. These individuals have normal-sized trunks and unusually large heads with a prominent forehead. As the disorder affects only cartilage and bone formation, these individuals have normal intelligence and life spans. The disease is caused by a mutation in the fibroblast growth factor receptor 3 (FGFR 3), which inhibits normal cartilage growth. Seventy percent of the cases of achondroplasia dwarfism are sporadic, meaning the parents are normal in size. The genetic mutation appears to occur during the formation of the father's sperm and is found most commonly in the sperm of fathers advanced in age. Twenty-five percent of those with achondroplasia inherit the disorder in an autosomal dominant fashion from their parents - that is one or both of the parents have the disorder. If a parent with achondroplasia is married to a parent without achondroplasia, half of the children will have the disorder and half will be of normal stature. In the case where two parents have achondroplasia, 3 out of 4 children will have short stature, while 1 of 4 children will die within a few months of birth. Unfortunately, having two bad genes for FGFR 3 is lethal.

Proportional dwarfism is usually caused by a deficiency in the growth hormone axis, meaning either the person is not producing enough growth hormone or there is a disorder of the growth hormone receptor. Children born with growth hormone deficiency may suffer from hypoglycemia (low blood sugar), delayed development and jaundice. Unfortunately, boys with this disorder, if left untreated, may suffer from a micropenis. As adults those with proportionate dwarfism will look like little people, but tend to have reduced muscle and strength and increased fat composition. They will also tend toward baldness in older men with this disorder and suffer from impaired concentration and memory loss. Fortunately, in those children who are not producing enough growth hormone, they can receive daily injections of growth hormone to increase their size. Unfortunately, this is an expensive therapy that costs about $25,000 per year.

There is a subset of those with proportionate dwarfism who have a mutated growth hormone receptor. These individuals, also called Laron dwarfs, will not respond to growth hormone as children, but they will however respond to a hormone caused IGF-1. Hence, medical science and early pediatric intervention may help these individuals. There is a lot of social prejudice against those with dwarfism. In school, this social prejudice may take the form of teasing, ridicule and bullying from some classmates. This can lead to lifelong emotional damage.

Interestingly, dwarfs who may have a change in a single gene are most likely to be picked on by those who have multiple genetic deficits that have led to lower than normal intelligence or maturity. Yet, even as adults, most of us have prejudices we don't even realize as numerous studies have shown that dwarfs and short people are less likely to get hired, to get a promotion or be treated respectfully even when they are just or even more qualified than others. Education is an important key for a society that will allow equal opportunity for all and not just a select few that fit a transient societal view on what physical appearance is in for the day.

I say this, as other studies show that very attractive people by today's standards tend to (but not always) have lower intelligence, lower competence and lower skill levels versus others in similar positions. Hence, the take-home message is don't judge a book by its cover, but open the book and understand its content.

- Dr. Joseph De Soto, M.D., Ph.D., F.A.I.C. obtained his B.S. degree at La Sierra University and attended graduate school at Yale University. He then obtained his M.D. and Ph.D. at Howard University and did his postgraduate training at the National Institutes of Health. He can be reached at oncmed-research@hotmail.com